The present invention relates to electrode body structures for ablating interior regions of the human body and manufacturing methods of making the same.
Physicians make use of catheters today in medical procedures to gain access into interior regions of the body for ablating targeted tissue areas. These procedures, called electrophysiological therapy, are becoming more widespread for treating cardiac rhythm disturbances. It is important for the physician to control carefully and precisely these ablation procedures, especially during procedures that ablate tissue within the heart. During electrophysiological therapy, the physician introduces an ablation catheter through a main vein or artery, typically the femoral vein or artery, into the interior region of the heart that is to be treated. Placement of the ablation catheter within the heart is typically facilitated with the aid of a guide sheath. The physician then further manipulates a steering mechanism to place an ablation electrode carried on the distal tip of the ablation catheter into direct contact with the tissue that is to be ablated. The physician directs radio frequency energy from the ablation electrode through tissue to an indifferent electrode, or another catheter-mounted electrode, to ablate the tissue and form a lesion.
It has been determined that an expandable and collapsible electrode structure is advantageous for ablation of body tissue within a patient""s body. The electrode structure is maintained in a collapsed condition, i.e., in a low-profile condition, when inserting the catheter into and maneuvering the catheter through the vasculature of a patient. When the electrode structure reaches the target ablation sight, the electrode structure is expanded, i.e., in a large-profile condition. The expanded electrode structure allows larger and deeper lesions to be created in the body tissue. Alternatively, the expanded electrode structure allows vascular structures such as pulmonary veins to be electrically isolated from adjacent body tissue. In one implementation of an expandable and collapsible electrode structure, it has been proposed to manufacture the electrode structure out of a microporous material. An electrically conductive element is located within the interior of the electrode structure. In use, after the electrode structure is located at the target ablation sight, a medium containing ions is introduced into the interior of the electrode structure, causing the electrode structure to expand. High frequency RF energy is transmitted through the electrically conductive element and medium containing ions, to the body tissue for ablation of such tissue. Microporous electrode structures designed to automatically, consistently and easily fold upon itself when deflated can be introduced into the body through small introducing sheaths. Previous versions of the microporous electrode bodies collapsed into a somewhat larger profile and required a larger introducer for introduction into a vein or artery.
The present invention improves the functionality of microporous electrode structures used as active elements in RF ablation catheters.
In accordance with a first aspect of the present invention, an electrode assembly adapted to transmit electrical energy for ablating body tissue includes an expandable and collapsible non-compliant body made of a durable material and defining an interior adapted to receive a medium containing ions, the body including a porous region, an electrode adapted to transmit electrical energy located in the interior of the body, a microporous membrane located on the porous region of the non-compliant body, the microporous membrane sized to pass ions contained in the medium without substantial medium perfusion therethrough, to thereby enable ionic transport of electrical energy from the ion-containing medium to the exterior of the electrode assembly to ablate body tissue.
Implementations of the first aspect of the invention may include one or more of the following. The non-compliant body is made of a material from the group consisting of Nylon, PET, PeBax, IEBA and any of the polymers used in making an angioplasty balloon. The membrane is made of a material from the group consisting of regenerated cellulose, nylon, nylon 6, nylon 6/6, polycarbonate, poly(vinylidene fluoride), a poly(vinylidene fluoride) and poly(N-vinylpyrrolidone) combination, polyethersulfone, modified acylic copolymers, and cellulose acetate. The porous region of the non-compliant body includes pores having a pore size in the range of 5 to 1,000 microns. The microporous membrane includes pores having a pore size in the range of 0.001 to 0.100 microns. The non-compliant body includes an exterior surface and the microporous membrane is located on the exterior surface of the body. The non-compliant body includes an interior surface and the microporous membrane is located on the interior surface of the body.
A second aspect of the invention involves a method of manufacturing an electrode assembly adapted to transmit electrical energy for ablating body tissue. The method includes providing an expandable and collapsible non-compliant body made of a durable material and defining an interior adapted to receive a medium containing ions, the body including a porous region; providing an electrode adapted to transmit electrical energy in the interior in the body; and attaching a microporous membrane onto porous region of the non-compliant body, the microporous membrane sized to pass ions contained in the medium without substantial medium perfusion therethrough, to thereby enable ionic transport of electrical energy from the ion-containing medium to the exterior of the electrode assembly to ablate body tissue.
Implementations of the second aspect of the invention may include one or more of the following. The body has an exterior surface, and method further includes attaching the microporous membrane to the exterior surface. The body has an interior surface, and method further includes attaching the microporous membrane to the interior surface. The microporous membrane is attached to the body with a process selected from the group consisting of adhesive bonding and heat bonding. The non-compliant body is made of a material from the group consisting of Nylon, PET, IEBA or other materials used in angioplasty balloons. The membrane is made of a material from the group consisting of regenerated cellulose, nylon, nylon 6, nylon 6/6, polycarbonate, poly(vinylidene fluoride), a poly(vinylidene fluoride) and poly(N-vinylpyrrolidone) combination, polyethersulfone, modified acylic copolymers, and cellulose acetate. The porous region of the non-compliant body includes pores having a pore size in the range of 5 to 1,000 microns. The microporous membrane includes pores having a pore size in the range of 0.001 to 0.100 microns.
A third aspect of the invention involves an electrode assembly adapted to transmit electrical energy for ablating body tissue including an expandable and collapsible non-compliant body made of a durable material and defining an interior adapted to receive a medium containing ions, the body including a porous region having a plurality of pores, an electrode adapted to transmit electrical energy located in the interior of the body, a microporous coating located on the porous region of the non-compliant body and including microporous plugs located in the pores of the porous region, the microporous coating sized to pass ions contained in the medium without substantial medium perfusion therethrough, to thereby enable ionic transport of electrical energy from the ion-containing medium to the exterior of the electrode assembly to ablate body tissue.
Implementations of the third aspect of the invention may include one or more of the following. The non-compliant body is made of a material from the group consisting of Nylon, PET, IEBA, and other polymers used to make angioplasty balloons. The membrane is made of a material from the group consisting of regenerated cellulose, nylon, nylon 6, Nylon 6/6, polycarbonate, poly(vinylidene fluoride), a poly(vinylidene fluoride) and poly(N-vinylpyrrolidone) combination, polyethersulfone, modified acylic copolymers, and cellulose acetate. The porous region of the non-compliant body includes pores having a pore size in the range of 5 to 1,000 microns. The microporous coating includes pores having a pore size in the range of 0.001 to 0.100 microns.
A fourth aspect of the invention involves a method of manufacturing an electrode assembly adapted to transmit electrical energy for ablating body tissue. The method includes providing an expandable and collapsible non-compliant body made of a durable material and defining an interior adapted to receive a medium containing ions, the body including a porous region having a plurality of pores; providing an electrode adapted to transmit electrical energy in the interior in the body; providing a microporous coating on the porous region of the non-compliant body, the microporous coating including microporous plugs located in the pores of the non-compliant body, the microporous coating sized to pass ions contained in the medium without substantial medium perfusion therethrough, to thereby enable ionic transport of electrical energy from the ion-containing medium to the exterior of the electrode assembly to ablate body tissue.
Implementations of the fourth aspect of the invention may include one or more of the following. The step of providing the microporous coating includes dipping the porous region of the non-compliant body into a viscose solution and regenerating the viscose. The non-compliant body is made of a material from the group consisting of Nylon, PET, IEBA, and other polymers used to make angioplasty balloons. The coating is made of a material from the group consisting of regenerated cellulose, nylon, nylon 6, nylon 6/6, polycarbonate, poly(vinylidene fluoride), a poly(vinylidene fluoride) and poly(N-vinylpyrrolidone) combination, polyethersulfone, modified acylic copolymers, and cellulose acetate. The pores of the porous region of the non-compliant body have a pore size in the range of 5 to 1,000 microns. The microporous coating includes pores having a pore size in the range of 0.001 to 0.100 microns.
A fifth aspect of the invention includes an electrode assembly adapted to transmit electrical energy for ablating body tissue including an expandable and collapsible electrode body including a pair of non-compliant body ends and a microporous intermediate section joining the ends, the ends and intermediate section defining an interior adapted to receive a medium containing ions, an electrode adapted to transmit electrical energy located in the interior of the body, and the microporous intermediate section sized to pass ions contained in the medium without substantial medium perfusion therethrough, to thereby enable ionic transport of electrical energy from the ion-containing medium to the exterior of the electrode assembly to ablate body tissue.
Implementations of the fifth aspect of the invention may include one or more of the following. The non-compliant body ends are made of a material from the group consisting of Nylon, PET, IEBA, and other polymers used to make angioplasty balloons. The non-compliant body ends are angioplasty balloon ends. The microporous intermediate section is made of a material from the group consisting of regenerated cellulose, nylon, nylon 6, nylon 6/6, polycarbonate, poly(vinylidene fluoride), a poly(vinylidene fluoride) and poly(N-vinylpyrrolidone) combination, polyethersulfone, modified acylic copolymers, and cellulose acetate. The microporous intermediate section includes pores having a pore size in the range of 0.001 to 0.100 microns. The body ends are substantially funnel-shaped and the microporous intermediate section is substantially tubular.
A sixth aspect of the invention involves a method of manufacturing an electrode assembly adapted to transmit electrical energy for ablating body tissue. The method includes providing an expandable and collapsible non-compliant body made of a durable material; removing an intermediate section of the non-compliant body so as to form a pair of opposite non-compliant body ends; replacing the intermediate section of the non-compliant body with a microporous intermediate section; attaching the non-compliant body ends and the microporous intermediate section so that the ends and intermediate section define an interior adapted to receive a medium containing ions, the microporous intermediate section sized to pass ions contained in the medium without substantial medium perfusion therethrough, to thereby enable ionic transport of electrical energy from the ion-containing medium to the exterior of the electrode assembly to ablate body tissue; providing an electrode adapted to transmit electrical energy in the interior in the body.
Implementations of the sixth aspect of the invention may include one or more of the following. The non-compliant body ends are made of a material from the group consisting of Nylon, PET, IEBA, and other polymers used to make angioplasty balloons. The microporous intermediate section is made of a material from the group consisting of regenerated cellulose, nylon, nylon 6, nylon 6/6, polycarbonate, poly(vinylidene fluoride), a poly(vinylidene fluoride) and poly(N-vinylpyrrolidone) combination, polyethersulfone, modified acylic copolymers, and cellulose acetate. The microporous intermediate section includes pores having a pore size in the range of 0.001 to 0.100 microns. The body ends are substantially funnel-shaped and the microporous intermediate section is substantially tubular.
A seventh aspect of the invention involves a method of manufacturing an electrode assembly adapted to transmit electrical energy for ablating body tissue. The method includes providing an expandable and collapsible non-compliant body made of a durable material and defining an interior adapted to receive a medium containing ions, the body including a porous region having a plurality of pores; providing an electrode adapted to transmit electrical energy in the interior in the body; providing a microporous coating on the porous region of the non-compliant body, the microporous coating including microporous plugs located in the pores of the non-compliant body, the microporous coating sized to pass ions contained in the medium without substantial medium perfusion therethrough, to thereby enable ionic transport of electrical energy from the ion-containing medium to the exterior of the electrode assembly to ablate body tissue.
An eighth aspect of the invention includes a method of manufacturing an electrode assembly adapted to transmit electrical energy for ablating body tissue. The method includes providing an expandable and collapsible non-compliant body made of a durable material and defining an interior adapted to receive a medium containing ions; providing an electrode adapted to transmit electrical energy in the interior in the body; creating numerous micropores in the non-compliant body, the micropores sized to pass ions contained in the medium without substantial medium perfusion therethrough, to thereby enable ionic transport of electrical energy from the ion-containing medium to the exterior of the electrode assembly to ablate body tissue.
Implementations of the eighth aspect of the invention may include one or more of the following. The micropores are created using an ion-beam process. The micropores are located only in a central section of the body. The non-compliant body is made of a material from the group consisting of Nylon, PET, IEBA, and other polymers used to make angioplasty balloons. The non-compliant body is an angioplasty balloon. The micropores have a pore size in the range of 0.001 to 0.100 microns.
A ninth aspect of the invention involves an electrode assembly adapted to transmit electrical energy for ablating body tissue including an expandable and collapsible non-compliant body made of a durable material and defining an interior adapted to receive a medium containing ions, the body having a step-shaped configuration formed by a first-diameter portion and a second-diameter portion with a diameter greater than the first-diameter portion, an electrode adapted to transmit electrical energy located in the interior of the body, a microporous structure located in the first-diameter portion of the non-compliant body, the microporous structure sized to pass ions contained in the medium without substantial medium perfusion therethrough, to thereby enable ionic transport of electrical energy from the ion-containing medium to the exterior of the electrode assembly to ablate body tissue.
Implementations of the ninth aspect of the invention may include one or more of the following. The first diameter portion of the body includes a porous region and the microporous structure includes a microporous membrane adhered to the porous region of the body. The body includes an inside surface and the microporous membrane is adhered to the inside surface of the body. The body includes an outside surface and the microporous membrane is adhered to the outside surface of the body. The first diameter portion of the body includes a porous region having a plurality of pores, the microporous structure includes a microporous coating adhered to the porous region of the body, and the microporous coating includes microporous plugs located in the pores of the porous region of the body.
A tenth aspect of the invention involves a method of manufacturing an electrode assembly adapted to transmit electrical energy for ablating body tissue. The method includes providing an expandable and collapsible non-compliant body made of a durable material and defining an interior adapted to receive a medium containing ions, the body having a step-shaped configuration formed by a first-diameter portion and a second-diameter portion with a diameter greater than the first-diameter portion; providing an electrode adapted to transmit electrical energy in the interior in the body; providing a microporous structure in the first-diameter portion of the non-compliant body, the microporous structure sized to pass ions contained in the medium without substantial medium perfusion therethrough, to thereby enable ionic transport of electrical energy from the ion-containing medium to the exterior of the electrode assembly to ablate body tissue.
Implementations of the tenth aspect of the invention may include one or more of the following. The first diameter portion of the body includes a porous region, the microporous structure includes a microporous membrane, and the step of providing a microporous structure in the first-diameter portion of the non-compliant body includes adhering the microporous membrane to the porous region of the body. The body includes an inside surface and the microporous membrane is adhered to the inside surface of the body. The body includes an outside surface and the microporous membrane is adhered to the outside surface of the body. The first diameter portion of the body includes a porous region having a plurality of pores, the microporous structure includes a microporous coating, and the step of providing a microporous structure in the first-diameter portion of the non-compliant body includes dipping the porous region of the body in a viscose solution and regenerating the viscose. The step of providing a microporous structure in the first-diameter portion of the non-compliant body includes creating a plurality of micropores in the first-diameter portion using an ion-beam process.
Other and further objects, features, aspects, and advantages of the present inventions will become better understood with the following detailed description of the accompanying drawings.